Stainless Steel Casting Good Performance
Stainless steel: chromium content of more than 12% of the iron-based alloy known as stainless steel, stainless steel and acid-resistant steel in general. Stainless steel is resistant to atmospheric, Stainless Steel Casting steam and water and other weak corrosive media of steel, and acid-resistant steel is resistant to acid, alkali, salt and other chemical corrosive media corrosion of steel, stainless steel and acid-resistant steel in the degree of alloying are quite different , Stainless steel, although it has a stainless, but not necessarily acid; Stainless Steel Casting and acid-resistant steel are generally rusty, in the air or chemical corrosion medium can resist corrosion of a high alloy steel, stainless steel is a beautiful surface and Corrosion resistance, good, Stainless Steel Casting do not have to wait through the surface treatment of color, and play the inherent surface properties of stainless steel, Stainless Steel Casting used in a wide range of steel, usually called stainless steel. Stainless Steel Casting At present, stainless steel castings in the market has also been widely used, Stainless Steel Casting today Xiaobian for everyone to explain the four categories of stainless steel casting:
Classification of chemical composition Stainless steel Cr stainless steel and Cr, Ni stainless steel two categories. The corrosion resistance of stainless steel is mainly C content and precipitation of carbides, so corrosion-resistant stainless steel containing C as low as possible, Stainless Steel Casting usually C ≤ 0.08%, but the high temperature mechanical properties of heat-resistant steel is determined by its organization stability Of the carbide precipitation phase, so the heat-resistant steel containing C are higher, Stainless Steel Casting generally carbon content of 0.20% or more.
With chromium as the main alloying element, Stainless Steel Casting the amount of Cr is generally between 13% and 30%. Has a good resistance to oxidative media corrosion and the ability to withstand air oxidation at high temperatures, can also be used as heat-resistant steel. The welding performance of this kind of steel is poor. When the chromium content is more than 16%, the as-cast structure is coarse, Stainless Steel Casting and long-term insulation between 400-525 ℃ and 550-700 ℃, there will be "475 ℃" brittle phase and σ phase, Stainless Steel Casting so that steel brittle. The brittleness at 475 ° C is related to the ordering of Cr-containing ferrite. 475 ℃ brittle phase and σ phase brittleness, Stainless Steel Casting can be heated to 475 ℃ above and then fast to improve. The brittleness at room temperature and the brittleness of the post-weld heat affected zone are also one of the basic problems of ferritic stainless steel. Vacuum refining can be used to add trace elements such as boron, rare earth and calcium, Stainless Steel Casting or austenite forming elements such as Ni, Mu, N, Cu, etc.) approach to be improved. In order to improve the mechanical properties of the weld zone and the heat affected zone, a small amount of Ti and Nb are usually added to prevent grain growth in the heat affected zone. Commonly used ferrite steel ZGCr17 and ZGCr28. The impact toughness of this type of steel is low, in many cases by high nickel austenitic stainless steel replaced. Ni content of more than 2%, Stainless Steel Casting containing more than 0.15% of the amount of ferrite steel has a good impact performance.
Martensitic stainless steels include martensitic stainless steel and precipitated hardened stainless steel. In engineering applications, mechanical properties are the main purpose. Although these steels have good corrosion resistance in atmospheric corrosion and less aggressive corrosive media (such as water and certain organic media), their corrosion properties are often not tested. The chemical composition of the range is: Cr13% -17%, Ni2% -6%, C ≤ 0.06%. Metallic microstructure is mainly low carbon slat martensite, therefore, Stainless Steel Casting has excellent mechanical properties, strength index is more than twice the austenitic stainless steel,Stainless Steel Casting but also has a good process performance, Stainless Steel Casting especially welding performance. So in the important engineering applications occupy a very important position, is casting an important part of the field of stainless steel.